libopusdec: default to stereo for invalid number of channels
authorAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Mon, 14 Nov 2016 20:41:45 +0000 (21:41 +0100)
committerAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Sat, 26 Nov 2016 23:28:08 +0000 (00:28 +0100)
This fixes an out-of-bounds read if avc->channels is 0.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit 8c8f543b81aa2b50bb6a6cfd370a0061281492a3)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
libavcodec/libopusdec.c

index acc62f1..e6ca61a 100644 (file)
@@ -47,6 +47,13 @@ static av_cold int libopus_decode_init(AVCodecContext *avc)
     int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
     uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
 
+    avc->channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->channels == 1) ? 1 : 2;
+    if (avc->channels <= 0) {
+        av_log(avc, AV_LOG_WARNING,
+               "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
+        avc->channels = 2;
+    }
+
     avc->sample_rate    = 48000;
     avc->sample_fmt     = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
                           AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;